Recently, various types of display devices, such as an organic light-emitting display device and a liquid crystal display device, have been provided. The organic light-emitting display device is capable of displaying an image in a wide color gamut and therefore, is receiving attention as a next-generation display device. Such a wide color gamut display device may represent colors brilliantly and deeply. In particular, the organic light-emitting display device may represent a deep sea color, a sky color, and a green color in rich color.